Hydrogen peroxide production technology
Hydrogen peroxide chemical formula H₂O₂, commonly known as hydrogen peroxide. The appearance is colorless transparent liquid, is a strong oxidizing agent, and its aqueous solution is suitable for medical wound disinfection, environmental disinfection and food disinfection. Under normal circumstances, it will decompose into water and oxygen, but the decomposition rate is extremely slow, and the way to speed up the reaction is to add a catalyst - manganese dioxide or irradiation with short-wave radiation.
Physical property
Aqueous solution is colorless transparent liquid, soluble in water, alcohol, ether, insoluble in benzene, petroleum ether.
Pure hydrogen peroxide is a light blue viscous liquid with a melting point of -0.43 °C and a boiling point of 150.2 ° C. The molecular configuration of pure hydrogen peroxide will change, so the melting boiling point will also change. At the freezing point, the solid density is 1.71g/ g, and the density decreases with the increase of temperature. It is more associated than H₂O, so it has a higher dielectric constant and boiling point than water. Pure hydrogen peroxide is relatively stable, heated to 153 °C will be violently decomposed into water and oxygen, it is worth noting that there is no intermolecular hydrogen bond in hydrogen peroxide.
Hydrogen peroxide has a strong oxidation effect on organic matter and is generally used as an oxidizing agent.
Chemical property
1. Oxidation
(The lead white [basic lead carbonate] in the oil painting will react with hydrogen sulfide in the air to produce black lead sulfide, which can be washed with hydrogen peroxide)
(Alkaline medium required)
2. Reducibility
3. Add dilute sulfuric acid test solution (TS-241)5ml and potassium permanganate test solution (TS-193)1ml to 10% sample solution 10ml.
Bubbles should occur, and the color of potassium permanganate disappears. It is acidic to litmus. Explosive when exposed to organic matter.
4. Take a sample of 1g(accurate to 0.1mg) and dilute it with water to 250.0ml. Take 25ml of this solution, add 10ml dilute sulfuric acid test solution (TS-241) and titrate with 0.1mol/L potassium permanganate. 0.1mol/L per milliliter. Potassium permanganate is equivalent to hydrogen peroxide (H2O2)1.70mg.
5. In case of organic matter, heat decomposition releases oxygen and water, in case of chromic acid, potassium permanganate, metal powder reaction is severe. In order to prevent decomposition, trace stabilizers can be added, such as sodium stannate, sodium pyrophosphate, and so on.
6.. Hydrogen peroxide is an extremely weak acid: H2O2 =(reversible)=H++HO2- (Ka=2.4×10-12). Therefore, the peroxide of a metal can be regarded as its salt.
Main use
The use of hydrogen peroxide is divided into medical, military and industrial three kinds, daily disinfection is medical hydrogen peroxide, medical hydrogen peroxide can kill intestinal pathogens, suppurative coccus, pathogenic yeast, generally used for surface disinfection. Hydrogen peroxide has the effect of oxidation, but the concentration of medical hydrogen peroxide is equal to or less than 3%, wipe to the wound surface, there will be a burning feeling, the surface is oxidized into white and bubbling, it can be cleaned with water, after 3-5 minutes to restore the original skin color.
Chemical industry used for the production of sodium perborate, sodium percarbonate, peracetic acid, sodium chlorite, thiourea peroxide and other raw materials, tartaric acid, vitamins and other oxidants. The pharmaceutical industry is used as a fungicide, disinfectant, and oxidant for the production of Fumei double insecticide and 40l antibacterial agent. Printing and dyeing industry used as bleaching agent for cotton fabrics, VAT dyes after dyeing hair color agent. Used to remove iron and other heavy metals in the production of metal salts or other compounds. It is also used in electroplating solution to remove inorganic impurities and improve the quality of plating parts. It is also used for bleaching wool, raw silk, ivory, pulp, fat, etc. Hydrogen peroxide in high concentrations can be used as rocket fuel.
Civil: to deal with the smell of the kitchen sewer, to the pharmacy to buy hydrogen peroxide and water and washing powder into the sewer can be decontaminated, disinfect, sterilization;
3% hydrogen peroxide (medical grade) for wound disinfection;
Industrial law
Alkaline hydrogen peroxide process: The quinone air electrode for the production of alkaline hydrogen peroxide is characterized in that each pair of electrodes is composed of a positive plate, a plastic net, a cationic diaphragm and a quinone air cathode, and the upper and lower ends of the electrode working area are provided with a distribution chamber for entering the fluid and a collection chamber for discharging the fluid, and a throttle hole is provided at the fluid inlet. The multi-component electrodes adopt a limited dipole series connection method. The plastic hoses for the inlet and outlet of anode circulating alkali water are extended and then connected to the liquid collector. The multi-component electrode group is assembled by the unit plate.
Phosphoric acid neutralization process: It is characterized in that it is prepared from sodium peroxide aqueous solution by the following steps:
(1) Use phosphoric acid or sodium dihydrogen phosphate NaH2PO4 to neutralize sodium peroxide aqueous solution to pH9.0 ~ 9.7, so as to generate aqueous solutions of Na2HPO4 and H2O2.
(2) The aqueous solution of Na2HPO4 and H2O2 is cooled to +5 ~ -5℃, so that most of the Na2HPO4 is precipitated in the form of Na2HPO4•10H2O hydrate.
(3) The mixture containing Na2HPO4 •10H2O hydrate and hydrogen peroxide aqueous solution is separated in a centrifugal separator, so that the Na2HPO4 •10H2O crystal is separated from the aqueous solution containing a small amount of Na2HPO4 and hydrogen peroxide.
(4) The said aqueous solution containing a small amount of Na2HPO4 and hydrogen peroxide is evaporated in the evaporator to obtain steam containing H2O2 and H2O, while the concentrated salt solution of Na2HPO4 containing hydrogen peroxide flows out from the bottom and returns to the neutralization tank.
(5) The said steam containing H2O2 and H2O is fractionated under reduced pressure in a fractionator to obtain about 30%H2O2 product.
Electrolytic sulfuric acid method: 60% of sulfuric acid is electrolyzed to obtain perdisulfuric acid, and then hydrolyzed to obtain hydrogen peroxide with a concentration of 95%.
2-ethyl anthraquinone method: The main method of industrial scale production is 2-ethyl anthraquinone (EAQ) method. 2-ethylanthraquinone reacts with hydrogen at a certain temperature and pressure under the action of catalyst to produce 2-ethylhydroanthraquinone, and 2-ethylhydroanthraquinone reacts with oxygen at a certain temperature and pressure, and 2-ethylhydroanthraquinone is reduced to produce 2-ethylanthraquinone and hydrogen peroxide is produced at the same time, and an aqueous solution of hydrogen peroxide is obtained through extraction. Finally, qualified hydrogen peroxide aqueous solution, commonly known as hydrogen peroxide, is purified by heavy aromatics. This process is mostly used to prepare 27.5% hydrogen peroxide, and higher concentration hydrogen peroxide aqueous solution (such as 35% and 50% hydrogen peroxide) can be obtained by distillation.
